Air cooled condenser



Aug. 16, 1938. I c. STEENSTRUP 2$127,438

' AIR COOLED CONDENSER I Filed Jan. 18, 1936 Inventor: ChristianSteenstrup,

bld W His ttorneg.

4 view along the line Patented. Aug. 16, 193

PATENT OFFICE" AIR COOLED CONDENSER Christian Steenstrup, Schenectady,N. Y., assignor to General Electric Company, a corporation of New YorkApplication January 1a, 1936, Serial no. 59355 10 Claims.

My invention relates to air cooled condensers for refrigeratingmachines. More, particularly my invention relates to air cooledcondensers for refrigerating machines in which a tubular sheet 5 metalmember having a condensing chamber therein is provided, an annulus ofheat conducting fins or other intermediate supporting member beingarranged within the periphery of the tubular member. The tubular member.and

in intermediate supporting member are ordinarily pressed on acylindrical compressor easing or similar main supporting member. I havefound,

however, that when such condensers are pro- -duced by large scalequantity-production fac- 15 tory methods that the diameters of thesupportprising a tubular member having. a condensing chamber therein andmounted on anintermediate supporting member surrounding a main 30supporting member and an arrangement which readily provides an increasein the circumferential length of the tubular member due tothe internalstretching forces to which" it is subjected,

, the stretching in the tubular member being 10- 35 calized in aparticular part thereof.

' Further objects and advantages of my invention will become apparent asthe following descriptionproceeds and the features of-novelty andforming a part of this specification."

For a. better understanding of my invention,

reference may be had to the accompanying dfawing in which Fig. 1 is aside elevation of a portion of a refrigerator cabinet and refrigeratingmachine therefor provided with an air cooled condenser embodying myinvention; Fig. 2 isa plan view of the refrigerator shown in Fig. 1;Fig. Bis an enlarged elevation, partly in section, of the rear portionof the condenser shown in Fig. 1, and Fig. 4- is a fragmentary sectional44 of the condenser shown inFig.3. 1

Referring to the drawing, in Fig. .1 I have shown a householdrefrigerator cabinet having It is an object of my invention to providean,

a. refrigerating unit provided with an air cooled condenser embodying myinvention. In this unit a compressor and electric" drivingmotor thereforare arranged in a cylindical hermetically sealed steel casing lh mountedon a removable cabinet top H. Gaseous refrigerant, such as sul-. phurdioxide, is compressed by the motor driven compressor in the casing land is supplied therefrom to a tubular member I! having an air cooledcondensing chamber therein, which tubular member surrounds the casing l0and is supported on a zigzag annulus offins I3 interposed between. thetubular member and the casing. 1 The compressed gaseous refrigerantflowing through the condensing chamber-in the tubular member I2 iscooled and liquefied by air flowing upwardly over the surfaces of thetubular member l2 and between the tubular member and the casing l0 overthe surfaces of the heat conduct-' ing fins l3. I'h refrigerant soliquefied flows to a flow control ng float valve H from which it-is,supp1ied through a liquid line I5 to an evaporator l6 suspendedbelow the cabinet top II within l a food storage compartment l], whichthe evaporator is adapted to cool. The liquid refrigerant is'vaporizedin the evaporator 16 by the ab- .sorption of heat from the coolingcompartment ll and is collected in a longitudinal cylindrical header l8above the level of the liquid refrigerant therein, the header 18 beingnormally maintained about half full of liquid refrigerant. The vaporizedrefrigerant thus collected in the header i8 is returned to thecompressor in the casing Ill through a suction conduit l9 and the cycle'described is repeated and continued until the temperature. of thecooling compartment I1 is lowered to a desired value.

The tubular memberl2, which is preferably cylindrical in form, includesan outer sheet or portion of metal 20, and upper and lower inner 40portions or sheets of metal 2| and 22, respectively. Upper and lowerelongated sinuous indentations 23 and 24 are provided in the outer sheetof metal 20. A complementary elongated sinuous indentationfi is formedin the lower inher sheet of metal 22, the indentation 25 registeringwith the indentation 24., A similar com-- plementary elongated sinuousindentation is formed in the upper inner sheet of metal 2| and arrangedin registry with the indentation 23. The indentations are preferablystamped in the inner and outer sheets of metal by suitable dies. Aplurality of'rows of narrow transverse slots 2Q are punched or otherwiseformed in an extended end portion 21 of the outer sheet of metal 20,

2 The transverse slots 2 are provided in order to provide a relativelyweak transverse section in the tubular gnember which permits a limitedand localizedrincrease in the peripheral length of the completed tubularmember 12, as is hereinafter more fully described. The stamping andpunching operations, referred to above. are preferably completed-beforethe sheets of metal 2|, 2i and 22 are assembled to form the completedtubular member l2.

In assembling the sheets of metal 22, 2| and 22 to form the tubularmember l2, the inner sheets of metal 2| and 22 are preferably arrangedflat in face contact with the inner surface of the outer'sheet of metal2| and in such position that the end portion 21 of the outer sheetextends beyond the adjacent ends of the inner sheets 2| and 22. Thesheets of metal 2| and 22 are then hermetically secured to the outersheet 20 by line welds or a series of closely spaced spot welds, whichextend about the peripheries of the sheets 2| and 22 and along the edgesof the indentations 22, 24 and 2 throughout their length. After havingbeen thus secured together, the sheets of metal are bent into the formof a cylinder and the adjacent edges thereof are secured together. Theend part'of the extended portion 21 of the outer sheet 20 is preferablylapped over-the opposite end portion of the sheet 20,-the transverseedge of the portion 21 being arranged in abutting relation with theadjacent transverse edge of the inner sheet 22 as best shown in Fig. 4.The overlapping portions of the sheet 20 are then welded or otherwiserigidly secured together.

A rectangular sheet of metal is bent into the form of a zigzag series offins l2 and these fins tute an annulus. The nns II form an intermediatesupporting member between the tubular member i2 and the main supportingmember or casing ii. The annulus thus formed is then pressed on to thecasing or s upporting member Ill. The pressing operation is preferablycarried out in the hydraulic press and for the machine illustrated apressure of about seven tons is required. The transverse slots 2| formedin the end portion 21 of the outer sheet of metal 20 permit a limitedamount of stretching in the end portion 21 so that a deformable joint isformed between the adjacent ends of the sheet of metal 20. The lengthand number-of the slots 22, as well as the distance therebetween, is soproportioned that the widening of the slots and consequent stretching ofthe total length of the end portion 21 will take place only when apredeter-' ,mined force tending to increase the peripheral of theassembly press and also in order to avoid excessive strains on theparts. Moreover, an excessive internal pressure tending to increase theperipheral length of the tubular member-i2 would tend to flatten theindentations 24 and 2| thus obstructing the flow of refrigerant throughthe passages formed thereby.. In the arrangement which I have provided,howeqer, substantially all of the stretching in the tubular member I2 islocalized in the extended portion 21 of the outer sheet 20 and it willbe noted that no refrigerant passages extend across this portion of thetubular member. The arrangement which I have provided to permit alimited and localized increase in peripheral length of the tubularmember i2 is especially adaptedfor use in manufacturing large quantitiesof condensers by quantity-production methods. when using such methods,the sheet metal-parts of the condenser are ordinarily formed in poweroperated punch presses and the like and, as a consequence, somevariations in dimensions are likely to occur due to wearing of the diesor variations in dimensions of replacement of the dies. It should alsobe noted that the stretching permitted in the extended portion 21 of thesheet 20 by the slots 28 is limited to substantially the exact amountrequired in order to maintain a uniform pressure during the assemblingoperation despite the multiplicity of variations in dimensions of theparts which may occur.

While I have shown a particular embodiment of my invention in connectionwith a compression type refrigerating machine designed for householduse, I do not desire my invention to be limited to the particularconstructionshow'n and described and I intend in the appended claims tocover all modifications within the spirit and scope of my invention.

I claim: 1. An air cooled condenser for a refrigerating machinecomprising a supporting member, a tubular member having a condensingchamber therein to provide a limited and localized increase in theperipheral length thereof due to the internal stretching forces to whichit is subjected.

2. An air cooled condenser for a refrigerating machine comprising asupporting member, a tubular sheet metal member having a condensingchamber therein and extending about said supporting member and arrangedin spaced relation thereto, means including an intermediate sup portingmember extending between said first named supporting member and saidtubular member for preventing relative movement therebetween, saidtubular member including complementary inner and outer tubular portionsof sheet metal defining an extended refrigerant passage, I

therebetween, J means for hermetically securing said portions of sheetmetal together, and means including a deformable joint for securing theadjacent ends of at least one of said portions of 3. An air cooledcondenser for a refrigerating machine comprising a supportingmember, anannulus of line extending about said supporting member, and a tubularmember having a condensing chamber therein and positioned on said finsso as to constitute an annulus, said tubular member having a transverseslot formed therein to provide a limited'and localized increase in the75' circumferential length thereof due to the internal stretching forcesto which it'is subjected.

4. An air cooled condenser for a refrigerating machinecomprising asupporting member, an annulus of fins extending aboutsaid supportingmember, and a tubular sheet metal member having a condensing chambertherein and positioned on said fins so as to constitute an annulus, saidannulus of fins extending about said supportingmember. and a tubularsheet metal member having a condensing chamber therein and positioned onsaid fins so as to constitute-an annulus, said tubular member includingcomplementary inner and outer tubular sheets of metal, and means forhermetically securing said sheets of metal together in face contact, atleast one of said sheets of metal having an indentation formed thereincooperating with the other of said sheets of metal ,to form an extendedrefrigerant circulatory passage therebetween, an end portion of one ofsaid sheets of metalextending beyondthe adjacent end of the other ofsaid sheets of metal, said end portion of said one sheet of metal beingsecured to the opposite end of said one sheet of metal, said end portionof said one sheet of metal havinga plurality of rows of transverse slotsformed therein and arranged in staggered relation to provide a limitedand localized increase in the length thereof due to the internalstretching forces to which said tubular member is subjected.

6. An. air cooled condenser for a refrigerating machine including' atubular member having a condensing chamber therein of substanllm annularconfiguration, and a support, said tubular member extending about 1 dsupporting member and being frictiony uredthereto and having a;relatively well: transverse section therein to facilitate ated andlmaliaed increase in the circierential length thereof due to theinternal stretching forces to which it is subjected.

7. An air cooled condenser for a refrigerating machine comprising asupporting member, a tubular member having a condensing chamber thereinand extending about said supporting member and arranged in spacedrelation thereto, and means including an intermediate supporting memberextending between said first named supporting member and said tubular"member for preventing relative movement therebetween, said tubularmember having a plurality of rows of transverse slots formed therein andarranged in staggered relation to provide a limited and localizedincrease in the peripheral length thereof due to the internal stretchingforces to which it is subjected.

8. An air cooled condenser for a refrigeratingmachine including atubular member having'a condensing chamber therein, said tubular memberhaving a relatively weak transverse section therein to facilitate alimited and localized increase in the peripheral length thereof due tothe internal stretching forces to which it is subjected. 9.'An aircooled condenser for a refrigerating machine including a tubular memberhaving a condensing chamber therein extending about a major portion ofthe periphery of said tubular member and leaving a. minor portion of theperiphery thereof free of said bpndensing chamber, and means including atransverse slot formed in said minor portion of the periphery of saidtubular member for facilitating a limited and localized increase in theperipheral length of said tubular member and occurring insaid minorpor-' tion of the periphery thereof due to the internal stretchingforces to which itis subjected.

10. An air cooled condenser for a refrigerating machine includingcomplementary inner and outer tubular portions of sheet metal definingan extended refrigerant passage therebetween, means for-hermeticallysecuring said portions of said sheet metal together, and means includingadeformable joint for securing the adjacent ends of at least one of saidportions of sheet metal together to provide a limited and localizedincrease in the peripheral length thereof due to the internal stretchingforces to which it is subjected.

BTIAN SSTRUP.

